Muffler for internal combustion engines

ABSTRACT

A muffler for internal combustion engines including a hollow casing having a plurality of baffle elements positioned therein which cause the gases to make a plurality of 180* turns as the gases move therethrough. The cross-sectional area of the passageway through which the gases flow is as large or larger than the inlet port and the outlet port of the muffler so that little, if any, back pressure is created as the gases move through the muffler. Gas currents are trapped in &#39;&#39;&#39;&#39;alcoves&#39;&#39;&#39;&#39; adjacent the baffle elements which enhance the flow of gases through the muffler and which also serve to equalize the pressure within the muffler.

[ 72] Inventors United States Patent Theo A. Latch 808 West Main Street, Marshalltown, Iowa 50158;

Russell A. Cmey, 102 Cherry Street, Marshalltown, Iowa 50158; Gordon K.

- Edwards. 11.11. #1, Albion. Iowa 50005 [21] AppLNo. 757,234

[22] Filed Sept. 4, 1968 [45] Patented July 6, 1971 [54] MUFFLER FOR INTERNAL COMBUSTION Primary Examiner-Robert S. Ward, Jr. Attorney- Zarley, McKee & Thomte ABSTRACT: A muffler for internal combustion engines including a hollow casing having a plurality of bafi'le elements positioned therein which cause the gases to make a plurality of 180 turns as the gases move therethrough. The cross-sectional area of the passageway through which the gases flow is as large or larger than the inlet port and the outlet port of the muffler so that little, if any, back pressure is created as the gases move through the muffler. Gas currents are trapped in alcoves" adjacent the baffle elements which enhance the flow of gases through the muffler and which also serve to equalize the pressure within the muffler.

MUFFLER FOR INTERNAL COMBUSTION ENGINES Conventional mufflers forinternal combustion engines create objectionable back pressure which reduces upper cylinder lubrication and which causes the engine valves to be burned. Additionally, the conventional mufflers are not satisfactorily efficient and do not adequately muffle the engine exhaust. The conventional mufflers usually direct the gases through a plurality of small openings which'become clogged during use and which obviously reduces the efficiency of the muffler. These mufilers also cause areas of low pressure to be created therein and these low-pressure areas are intermittently relieved which causes objectionable noises to be produced.

Therefore, it is a principal object of this invention to provide a muffler device for internal combustion engines which is efiicient.

A further object of this invention is to provide a muffler for an internal combustion engine. including a plurality of baffle elements therein which cause the gases to make a plurality of substantially 180 turns.

A further object of this invention is to provide a muffler for an internal combustion engine wherein air currents are trapped in alcoves thereby enhancing the flow of gases through the muffler.

A further object of this invention is to provide a muffler for aninternal combustion engine which equalizes the pressure therein thereby avoiding undesirable noise.

A further object of this invention is to provide a muffler for an internal combustion engine wherein the gases are passed through a passageway in the muffler, the passageway having a cross-sectional area as large or larger than the inlet and outlet openings of the muffler. l

. A further object of this invention is to provide a muffler for an internal combustion engine which eliminates crosscurrents being created therein.

A further object of this invention is to provide a muffler for an internal combustion engine wherein a uniform flow of gases is provided therethrough by cushioning alcoves.

A further object of this invention is to provide a muffler for an internal combustion engine wherein air currents are trapped in pressurized and energized alcoves.

A further object of this invention is to provide a muffler for an internal combustion engine .which does 'not impose back pressure on the engine thereby enhancing upper cylinder lubrication.

A further object of this invention is to provide a muffler for an internal combustion engine which eliminates the pulsating effect of the gases passing therethrough.

A further object of this invention is to provide a muffler for an internal combustion engine which operates at high pressures.

A further object of this invention is to provide a muffler for an internal combustion engine wherein the muffler may be used for engines of various horsepowers.

A further object of this invention is to provide 'a muffler for internal combustion engines wherein the inlet and outlet openings are substantially the same diameter.

A further object of this invention is to provide a muffler for an internal combustion engine which may be stacked in relation to other mufilers.

. A further object of this invention is to provide a muffler for internal combustion engines including diagonally disposed bafile elements thereby causing the gases to travel a substantially great distance before passing out of the muffler.

A further object of this invention is to provide a muffler for internal combustion engines which is economical of manufacture, durable in use and refined in appearance.

These and other objects will be apparent to those skilled in the art.

This invention consists in the construction, arrangements, and combination of the variousparts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings in which:

FIG. 6 is a sectional view of the muffler of FIG. 5 as seen along lines 6-6, the broken lines indicating additional mufflers in a stacked relationship;

FIG. 7 is a fragmentary longitudinal sectional view of another modified form of the mufiler;

FIG. 8 is a sectional view as seen along lines 8-8 of FIG. 7;

FIG. 9 is a fragmentary longitudinal sectional view of another modified form of the muffler;

FIG. 10 is a sectional view as seen along lines 10-10 of FIG. 9;

FIG. 11 is a partial perspective view of the muffler of FIG. 9 with portions thereof cut away to more fully illustrate the invention;

FIG. 12 is a fragmentary longitudinal sectional view of another modified form of the muffler;

FIG. 13 is a sectional view as seen along lines 13-13 of FIG. I2; and

FIG. 14 is a sectional view as seen along lines 14-14 of FIG. 12.

With respect to the muffler 10in FIGS. 1 and 2, the numeral 12 generally designates a hollow metal casing 12 having an inlet pipe 14 at one end thereof and an outlet pipe 16 at the other end thereof. For purposes of description, casing 12 will be described as having atop 18, bottom 20, and opposite sides 22 and 24. A plurality of angularly disposed baffle elements 26 extend inwardly from wall 24 and have their inner ends terminating short of wall 22 as illustrated in FIG. 1 while a plurality of bafile elements 28 extend inwardly from wall 22 and have their inner ends terminating short of wall 24 as also illustrated in FIG. 1. The positioning of bafile elements 26 and 28 define a passageway 30 through which the gases pass. The cross-sectional area of the passageway 30 is as large or larger than the cross-sectional area of either of the inlet pipe 14 or outlet pipe 16 thereby preventing initial expansion of the gases which would then be compressed prior to leaving the outlet pipe 16 which would cause objectionable back pressure on the engine. As the gas passes through the muffler of FIG. 1 in the path generally designated by the large arrows, a plurality of alcoves 32 are created adjacent the baffle elements in which air currents and gas currents are trapped and which are energized and pressurized by the flow of gases through the muffler. The gas in the alcoves 32 has a pressure which is equal to or higher than the pressure of the gas flowing through the passageway 30. The alcoves 32 contain the cooler and heavier gases because of the centrifugal force created by the gas being turned in the plurality of substantially turns by the baffle elements. The gas in the alcoves 32 rotates in the manner illustrated by the circular arrows and thus lubricate or enhance the flow of gas through the passageway 30 adjacent thereto. If the gas pressure of the stream of gas in passageway 30 should rise, it is relieved in the alcoves 32. If the pressure in the gas stream in passageway 30 should drop, the pressure in the alcoves 32 equalizes the pressure. The equalizing of the pressure by the alcoves 32 eliminates objectionable noises which are created by such a pulsating effect. As previously stated, the gas in the alcoves 32 is cooler and heavier than the gas in the passageway 30 or the main stream of flow through the muffler. The hot gases passing through the muffler do not tend to penetrate the cooler alcoves 32 and thus we have a muffler which runs cooler than conventional mufflers. It can also be appreciated that the plurality of angularly disposed baffles causes the gas passing through the muffler to travel a considerable distance in relation to the length of the muffler.

another modified form of the The muffler 34 of FIGS. 3 and 4 is generally comprised of a hollow metal casing 36 having an inlet pipe 38 at one end thereof and a discharge pipe 40 at its other end as illustrated in Figure 3.

For purposes of description, casing 36 will be described as including a top 42, bottom 44 and opposite sidewalls 46 and '48. A vertical wall member 50 extends between top 42 and bottom 44 froni the intake end of the muffler and terminates short of the discharge end of the muffler as best illustrated in FIG. 3. A plurality of baffle elements 52 are secured to wall 50 and extend inwardly therefrom while a plurality of baffles 54 are secured to sidewall 48 and extend inwardly therefrom in the manner also best illustrated in FIG. 3. The baffle elements .52 and 54 define a passageway 56 which is in communication with the interior of inlet pipe 38. Casing 36 is also provided with a vertical wall 58 extending between the top 42 and bottom 44 from the discharge end of the muffler and terminating short of the inlet end of the muffler as seen in FIG. 3. A plurality of baffle elements 60 are secured to wall 58 and extend inwardly therefrom while a plurality of baffle elements 62 are secured to sidewall 46 and extend inwardly therefrom between the baffle elements 60. Vertical walls 50 and 58 define a passageway 56 therebetween while the baffle elements 60 and 62 define a passageway 56" therebetween. Thus, the gases enter the muffler through the inlet pipe 38 and passes through passageways 56, 56, 56" and-passes out of the muffler through outlet pipe 40. The baffle elements in the muffler cause the gases to make a plurality of 180 turns and create the alcoves 64 adjacent the baffle elements which function identically to the alcoves 32 in mufi'ler I and will not again be described.

' The muffler 66 seen in FIGS. and 6 is generally comprised of a hollow cylindrical casing 68 havingan inlet pipe 70 extending laterally from its inlet wall 72 and an outlet opening 74 extending outwardly through its outlet wall 76. Muffler 66 is provided with an interior wall 78 having a diameter less than the diameter of casing 68. A discharge pipe 80 is centrally positioned in the casing 68 and has an opening 82 in communication with the interior of the area defined by wall 78. The rearward end of pipe 80 is open to form the discharge opening 74 previously described. Casing 68 is provided with a plurality of baffle elements 84 extending radially inwardly therefrom while wall 78 has a plurality of baffle elements 86 extending radially outwardly therefrom between the baffle elements 84 to define a passageway 88 therebetween. A plurality of baffle elements 90 are secured to wall 78 and extend radially inwardly therefrom while a plurality of baffle elements 92 are secured to pipe 80 and extend radially outwardly therefrom between the baffle elements 90 as illustrated in FIG. 5. Baffle elements 90 and 92 define a passageway 88 therebetween. A baffle 94 extends between casing 68 and wall 78 while a wall 96 extends between wall 78 and pipe 80. It should be noted that all of the baffle elements and wall members just described are secured to and extend between the walls 72 and 76 as illustrated in FIG. 6. Thus, the gases enter the muffler through the inlet pipe 70 and is directed through the passageway 88 by the baffle elements 84 and 86'so that the gases are required to make a plurality of substantially 180 turns. The gases pass through passageway 88 completely around the muffler until wall 94 is encountered which directs the gases into the passageway 88' between the baffle elements 90 and 92 which also cause the gases to be directed in a plurality of 180 turns until wall 96 is encountered which directs the gases into the pipe 80 and out of the outlet opening 74. As in mufflers l0 and 34, a'plurality of alcoves 98 are created which function in the same manner as the alcoves 32 in FIG. 1. In FIGS. 5 and 6, broken lines generally designated by the reference numeral 100 and 102 have been depicted to illustrate that more than one inlet pipe maybe utilized so that the muffler 66 could receive exhaust gases from a plurality of manifolds. FIG. 6 il- 'lustrates by way of broken lines the manner in which 8ddI-',

tional mufflers 66' and 66" may be stacked with relationship-- to muffier 66 if desired. The muffler 66' is identical to muffler,

66 and would have its normal dischargeopening in communi- 66" would have its inlet opening in communication with the inlet opening of muffler 66' in the manner illustrated in FIG. 6

Another form of the muffler is seen in FIGS. 8 and is generally designated by the reference numeral 1: andis seen to include a hollow metal casing 106 having an let pipe 108 at one end thereof and an outlet pipe 1l0 a t th'e'other end thereof. For purposes of description, muffler 104 will be described as including a top 112, bottom 114 and opposite sidewalls 116 and 118. A plurality of baffle elements are secured to wall 116 and extend inwardly therefrom'at an angle thereto seen in FIG. 7. A plurality of baffle elements 122 are secured to the interior of wall 118 and extend inwardly therefrom at an angle thereto as illustrated in FIG. 7. As seen in FIG. 7, the baffle elements 120 and 122 are alternately spaced and the inner ends thereof terminate in approximately the same plane and define a passageway I24 therebetween. The gases enter the muffler through the inlet opening 106 and pass through the muffler between the baffle elements 120 and 122 in the passageway 124 and out of the muffler through the outlet pipe 110. The battle elements cause the gases to make a plurality of substantially 180 turns and the centrifugal force of the gases create the alcoves 124 adjacent the baffle elements. As in the mufflers previously described, the cross-sectional area of the passageway 124 through which the gases pass is as large or larger than the cross-sectional area of either the inlet pipes or outlet pipes. Also, the alcoves 124 function in the identical manner as the alcoves previously described.

Another form of the invention is illustrated in FIGS. 9 and 10 and is generally designated by the reference numeral 126. Muffler 126 is generally comprised of a hollow metal casing 128 having a top 130, bottom 132, and opposite sidewalls 134 and 136. An inlet pipe 138 is mounted on one end of the easing 128 while an outlet pipe 140 is mounted on the other end of the casing 128. Casing 128 has a plurality of baffle elements I42 secured to its sidewall 134 which extend inwardly therefrom as illustrated in FIGS 9. and 10 while sidewall 136 has a plurality of baffle elements 144 secured thereto and extending inwardly therefrom as illustrated in FIG. 9. The baffle elements 142 and 144 are triangular in shape and are alternately arranged to define a passageway 146 therebetween through which the gases pass. Thus, the gases enter the muffler through the inlet pipe 138 and are caused to make a plurality of substantially 180 turns by the triangular baffle elements 142 and 144 and are discharged through the outlet pipe 140. The cross-sectional area of the passageway 146 is as great as or greater than the cross-sectional area of either the inlet pipe 138 or outlet pipe 140. The centrifugal force of the gases passing through the muffler create a plurality of alcoves 150 adjacent the baffle elements and these alcoves function in the identical manner to the alcoves 32 described in muffler 10.

Still another form of the invention is illustrated in FIGS. l2, l3 and I4 and is generally designated by the reference numeral 150. Muffler 150 is generally comprised of a hollow metal casing 152 having a top 154', bottom 15 6, and opposite sidewalls 158 and 160. An inlet pipe 162 is mounted on one end of the casing 152 while an outlet pipe 164 is mounted on the other end of the casing 152. A bafile 166 is secured to the inside surface of wall 158 and extends inwardly therefrom as illustrated in FIG. 12. A baffle 168 is provided in casing 152 and has a V-shaped portion 170 adjacent sidewall and a baffle wall portion 172 extending therefrom towards the other end of the casing parallel to sidewall 158. Baffle wall portion 172 is provided with an arcuate end portion 174 (FIG. 12). Casing 152 is also provided with a baffle 176 extending inwardly from wall 158 away from outlet pipe 164. Baffle 178 extends longitudinally from the inner end of baffle 176 towards inlet pipe 162 between wall l60jand baffle wall portion 172. I

The gases enter the muffler through theinlet pipe 16 and contact the baffles 166 and V-shaped portion 170, thence through passageways 180, 182 and 184 and outwardly through the outlet pipe 164. Baffle 166, V-shaped portion 170, arcuate end portion 174 and baffles 176 and 170 cause the gas to make a plurality of substantially 180 turns. The cross-sectional area of each of the passageways are as great as or greater than the cross-sectional areas of either the inlet pipe 162 or outlet pipe 164. The centrifugal force of the gases passing through the mufflers create a plurality of alcoves 186 adjacent the baffle elements and these alcoves function in the identical manner to the alcoves 32 described in muffler 10.

in each of the embodiments illustrated in the drawings, the cross-sectional area of the inlet pipe is approximately equal to that of the cross-sectional area of the outlet pipe while the passageway through which the gases pass through the muffler is as great as or greater than the cross-sectional area of either of the inlet pipe or the outlet pipe. This configuration controls the expansion of the gases in the muffler and does not require that the gases be compressed prior to being discharged from the muffler thereby eliminating objectionable back pressure on the engine which therefore improves upper cylinder lubrication of the engine. The alcoves formed or created in each of the mufflers lubricate the flow of gas through the muffler and equalizes the pressure in the muffler to eliminate objectionable noises as described in the operation of muffler l0. Objectionable gas crosscurrents are also eliminated in all of the embodiments illustrated in the drawings which thereby increases the efficiency of the unit. Thus it can be seen that the embodiments described above provide a muffler which not only operates at a cooler temperature but eliminates objectionable pulsating effects thereby providing a quieter muffler. The

quietness of the muffler is achieved by causing the gases to make the large number of substantially 180 turns which causes the gases to be cushioned in the alcoves and it can be appreciated that the more turns created the quieter the muffler will be.

Preferably, the muffler is constructed of a magnesium material and could be cast since it does not require the abundance of small holes as are found in conventional mufflers. The absenceof the small holes also insures that the muffler will efficiently operate since it is self-cleaning and will not become clogged. The absence of small perforated baffles and the position of the baffles in a plane perpendicular to at least one wall or the longitudinal axis of the housing makes the instant mufflers very adaptable for construction by casting which is a result totally unattainable by the mufflers used on modern vehicles. The mufflers shown can be cast in two separate halves, or can be cast in their entirety or substantial entirety under modern casting methods. This substantially im proves the economics of manufacture. While the mufflers described herein have been described as having the inlet and outlet openings on the opposite ends thereof, it should be noted that the inlet and outlet openings could be mounted on the sides of the muffler if desired. Thus it can be seen that the mufflers accomplish all of their stated objectives.

Some changes may be made in the construction and arrangement of our muffler for internal combustion engines without departing from the real spirit and purpose of our invention, and it is our intention to cover by our claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

We claim:

1. A muffler for an internal combustion engine, comprising,

a hollow casing having opposite sidewalls, opposite ends, a

top, and a bottom; said casing having an inlet port in one of said ends and an outlet port in the other of said ends;

a first baffle secured to the inside surface of one of said sidewalls adjacent said one end of said casing and extending inwardly towards said one end of said casing;

a second baffle secured to the inner end of said first baffle and extending inwardly towards said other end of said casing;

a third baffle secured to the inner end of said second baffle and extending toward said other end of said casing parallel to said other sidewall and terminating short of said other enda fourth baffle secured to the inside surface of said other sidewall between said third baffle and said other end of said casing and having its inner end portion extending inwardly therefrom towards said one end; and a fifth baffle secured to said inner end portion of said fourth bafile and extendingtowards said one end of said casing parallel to said one sidewall between said one sidewall and said third baffle, said fifth baffle terminating short of said first and second baffles. 2. The mufiler of claim 1 wherein a sixth baffle is secured to said other sidewall adjacent said one end andextends inwardly towards said one end between said one end and said first and second baffles.

3. The muffler of claim 1 wherein an arcuate end portion is provided on the free end of said third baffle which extends towards said one end between said other sidewall and said third baffle.

4. A muffler for an internal combustion engine, comprising a hollow casing having inlet and outlet ports formed therein; a plurality of baffle elements positioned in said casing between said inlet and said outlet ports so that the exhaust gases entering said inlet ports and passing through said casing will be deflected by said baffle elements, thereby causing the gases to make a plurality of substantially turns before being discharged from said outlet port;

said baffle elements being solid in construction so as to prevent gases from passing therethrough;

said baffle elements being spaced so as to create a passageway therebetween, said passageway having a cross-sectional area substantially the same as the crosssectional area of said inlet port to prevent expansion of gases within said casing.

5. The muffler of claim 4 wherein said hollow casing has parallel sides, parallel spaced-apart baffle elements extending longitudinally within said casing parallel to said sides to provide a plurality of elongated longitudinally extending passageways in said casing; said baffle elements having substantially smooth surfaces which are free from projections protruding into said passageways; one of said passageways being in communication with said inlet port; another of said passageways being in communication with said outlet port; and baffle means in said casing positioned to divert gases entering said casing from said inlet port longitudinally through one of said passageways in a first direction, and thence longitudinally through a second adjacent passageway in an opposite direction, whereby said gases are progressively diverted longitudinally through said passageways from said inlet port to said outlet port.

6. The muffler of claim 4 wherein said baffle elements are alternately spaced so as to cause said gases to form gas cushioning alcoves adjacent thereto, the gas in said alcoves being energized and pressurized by the flow of gases through the casing.

7. The muffler of claim 4 wherein the cross-sectional area of said inlet and outlet ports is substantially the same. 

1. A muffler for an internal combustion engine, comprising, a hollow casing having opposite sidewalls, opposite ends, a top, and a bottom; said casing having an inlet port in one of said ends and an outlet port in the other of said ends; a first baffle secured to the inside surface of one of said sidewalls adjacent said one end of said casing and extending inwardly towards said one end of said casing; a second baffle secured to the inner end of said first baffle and extending inwardly towards said other end of said casing; a third baffle secured to the inner end of said second baffle and extending toward said other end of said casing parallel to said other sidewall and terminating short of said other end; a fourth baffle secured to the inside surface of said other sidewall between said third baffle and said other end of said casing and having its inner end portion extending inwardly therefrom towards said one end; and a fifth baffle secured to said inner end portion of said fourth baffle and extending towards said one end of said casing parallel to said one sidewall between said one sidewall and said third baffle, said fifth baffle terminating short of said first and second baffles.
 2. The muffler of claim 1 wherein a sixth baffle is secured to said other sidewall adjacent said one end and extends inwardly towards said one end between said one end and said first and second baffles.
 3. The muffler of claim 1 wherein an arcuate end portion is provided on the free end of said third baffle which extends towards said one end between said other sidewall and said third baffle.
 4. A muffler for an internal combustion engine, comprising a hollow casing having inlet and outlet ports formed therein; a plurality of baffle elements positioned in said casing between said inlet and said outlet ports so that the exhaust gases entering said inlet ports and pasSing through said casing will be deflected by said baffle elements, thereby causing the gases to make a plurality of substantially 180* turns before being discharged from said outlet port; said baffle elements being solid in construction so as to prevent gases from passing therethrough; said baffle elements being spaced so as to create a passageway therebetween, said passageway having a cross-sectional area substantially the same as the cross-sectional area of said inlet port to prevent expansion of gases within said casing.
 5. The muffler of claim 4 wherein said hollow casing has parallel sides, parallel spaced-apart baffle elements extending longitudinally within said casing parallel to said sides to provide a plurality of elongated longitudinally extending passageways in said casing; said baffle elements having substantially smooth surfaces which are free from projections protruding into said passageways; one of said passageways being in communication with said inlet port; another of said passageways being in communication with said outlet port; and baffle means in said casing positioned to divert gases entering said casing from said inlet port longitudinally through one of said passageways in a first direction, and thence longitudinally through a second adjacent passageway in an opposite direction, whereby said gases are progressively diverted longitudinally through said passageways from said inlet port to said outlet port.
 6. The muffler of claim 4 wherein said baffle elements are alternately spaced so as to cause said gases to form gas cushioning alcoves adjacent thereto, the gas in said alcoves being energized and pressurized by the flow of gases through the casing.
 7. The muffler of claim 4 wherein the cross-sectional area of said inlet and outlet ports is substantially the same. 